US1312773A

US1312773A - Telephone-exchange system

Info

Publication number: US1312773A
Authority: US
Publication date: 1919-08-12
Anticipated expiration: 1936-08-12

Description

R. S. WILBUR.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION man SEPT- 25. 1917.

1 3 1 2,77 3 r Patented Aug. 12, 1919.

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' UNITED STATES PATENT OFFICE.

RAY S. WILBUR, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Aug. 12, 1919.

Application filed September 25, 1917. Serial No. 193,097.

To all whom it may concern Be it known that I, RAY S. WILBUR, a citizen of the United States, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephoneexchange systems and has for its 0l)]60t the production of improved signaling means for such systems.

In accordance with this invention, a llnk circuit employed for interconnectlng telephone lines is provided with a fast operating and a slow operating relay which cooperate with a supervisory relay to connect interrupter mechanism; in c1rc u1t w th a supervisory lamp to cause the intermlttent operation thereof, thereby to furnish a signal to the operator that a recall has been made on one of the connected telephone lines.

For a more complete understanding of this invention reference should be had to.

the following description considered in connection with the accompanylng drawlng illustrating one embodiment thereof.

There is shown in the drawing a local subscribers telephone line A which term nates at a local switchboard X at which is located the incoming end of a toll switching trunk circuit D. There is also shown a toll line B which terminates at a tollswitch board Y at which is located the outgoing end of the toll switching trunk circuit D and a toll cord circuit C which s employed for forming a portion of the connection between the toll line B and the local line A. The central office apparatus located to the right of the dotted line 2-9-2 is preferably located in the toll office, while that shown to the left of the llne 2-2 is preferably located at the local central oflice. The apparatus shown within the dotted rectangle E is common to a plurality of cord circuits.

In systems of the character disclosed in the drawing, the toll operator in charge of the toll cord circuit C usually receives from a recording operator, also located at the toll,

' office, a ticket giving the information as to the calling subscriber andthe called party-- either by number or name. The toll operator may then connect the operators telephone set with an order wire circuit (not shown) which extends from the toll board to a toll switching operators posi-. tion at the local board, the latter operator being in charge of the incoming end of to be used. At anyrate, the toll switching operator inserts the ping of the proper in coming toll switching trunk into a jack of the desired local line and the toll operator releases the order wire key and inserts plug 5 of cord circuit G into the outgoing jack of the proper toll switching trunk. Trunk circuit D merely serves to extend the telephone line A to the toll switchboard Y, and for the purpose of the present invention, the trunk circuit D may be considered as a portion of the telephone line A which may therefore be considered as terminating at switchboard Y.

The toll operator may designate the Assuming the assigned toll switching coining end thereof in jack 7 of line A,

causes the operation of relay 8 of the trunk circuit and cut-oft relay 9 of the line circuit. If the toll operator has not already inserted plug 5 into jack 10- of the trunk circuit, lamp 11, associated with the incoming end of the call wire circuit, will be lighted over a circuit from battery through the lamp 11, lower alternate contact of relay 8, resistance 12 and normal contact of relay 13 to ground. If the toll operator inserts the plug 5 of cord circuit G into jack 10 before the toll switching operator inserts plug 6 into jack 7, relay 13 is operated over a circuit from battery through the left-hand Winding of relay 13, lower normal contact of relay 14, repeating coil winding 15, tip contacts of jacklO and plug 5,

impedance coil 16, winding of relay 17,

impedance coil 18, ring contacts of plug 5 and jack 10, repeating coil windlng 19, upper normal contact of relay 14, and the right-hand winding of relay 13 to ground. Relay 13, in operating, causes lamp 11 to light over a circuit from battery through the lamp 11, lower normal contact of relay 8, upper winding of relay 14, and alternate contact of relay 13 to ground.

Relay 14 is also operated over the circuit just traced. This relay in operating completes a circuit through its lower alternate contact which maintains relay 13 operated when the hereinbefore traced circuit of relay 13 is opened at the normal contacts of relay 14. The operation of this relay 14 prevents the operation of relay 17 and the consequent lighting of supervisory lamp 22. The insertion of plug 5 into jack 10 also causes the operation of relay 20 over a circuit from battery through the left-hand winding of relay 20, sleeve contacts of the plug 5 and jack 10, and resistance 21 to ground.

Relay 20, in operatmg, completes a 011'- cuit for slow operating relay 23, and fast operating relay 24. Relay 24, upon belng energized over a circuit from battery through the lamp 22'," right-hand winding of relay 24 and left-hand contact of relay 20 to ground, opens its normal contact which is in circuit with slow operating relay 23, whereby this slow operating relay 23 does not have time to attract its armatures and close its contacts before its circuit is opened at the normal contact of relay 24. The right-hand winding of relay 24 is of high resistance so that lamp 22 Wlll not be lighted when in circuit with this high resistance winding. The left-hand winding of this relay 24 is of low resistance so that when the lamp 22 is included in circuit therewith, the lamp will be lighted. Relay 20 in operating also causes the operation of relay 25 which is a fast operating relay. Relay 26 is slow in operating, so that it is not sufliciently energized to at tract its armature before relay 25 attracts its armature and opens the circuit of relay 26.

If the toll operator inserts plug 5 into Jack 10 before the toll switching operator inserts plug 6 into jack 7, the lighting of the lamp 11 serves as a signal to the toll switching operator that the toll operator has plugged into the proper toll swltchmg trunk. The toll switching operator may then insert plug 6 into jack 7, whereupon relay 8 operates, extinguishing the lamp 11 and causing the release of relay 14. Relay 14 in releasing causes the operation of relay 17 over the hereinbefore traced circuit. The lamp 22 is immediately lighted upon operation of relay 17, and a short circuit is established for the righthand winding of relay 24, which thereupon releases its armatures. The release of the righthand armature causes the operation of the slow operating relay 23 over a circuit from battery through the winding of slow operating relay 23, contact 27 of listening key 23, normal contact of relay 23, normal contact of relay 24, and left-hand contact of relay 20 to ground. Relay 23 in operating completes a locking circuit for itself, which may be traced from battery through the winding of relay 23, contact 27 of listening key 28, lefthand alternate Contact of relay 23, and lefthand contact of relay 20 to ground. The closure of the right-hand contact of relay 23 connects interrupter 29 to the left-hand contact of relay 24, which is now open. The lighting of lamp 22 serves as a ringing signal to the toll operator so that this operator may now actuate ringing key 30 to connect a source of ringing current to the outgoing end of the toll switching trunk D, whereupon relay 31 is operated.

Relay 31 in operating causes the operation of relay 32 over a circuit from battery through the lower winding of relay 14, winding of relay 32 and the contact of relay 31 to ground. Relay 32 in operating connects a source of ringing current 33 to the local telephone line A to cause the operation of the call bell 34. Relay 14 is also operated over the circuit just traced. Supervisory relay 17 is released by the actuation of the ringing key 30. After ringing current is impressed upon line A for a short interval, the toll operator restores the ringing key to normal position, whereupon relays 31 and 32 are released, thereby disconnecting the source of ringing current from line A. Relay 14 also releases, causing the operation of relay 17 and the lighting of lamp Subscriber A, in response to the operation of call bell 34, removes the receiver from the switchhook, thereby causing the. operation of supervisory relay 35. Supervisory relay 35 in operating causes the operation of relay 14 over a circuit from battery through the lower winding of relay 14, contact of relay 35, upper winding of relay 14, and alternate contact of relay 13 to ground. Relay 14 in operating first establishes a holding circuit for relay 13, and then opens its normal contacts, thereby releasing relay 17, which in turn extinguishes the lamp 22. The release of relay 17 also removes the short-circuit from the high resistance winding of the right hand winding of relay 24, whereupon this relay operates, connecting the interrupter 29 through the low resistance winding of relay 24 to the lamp 22, which is thereupon intermittently lighted. The operator may then actuate.

listening key 28 to connect the operators telephone set to the talking strands of the cord circuit. The operation of listening key 28, opens its contact 27, which is in the locking circuit of relay 23. Relay 23 is thereupon released, disconnecting the interrupter from circuit relation with lamp 22. The lamp is thereby efi'aced.

The operator may now converse with the subscriber of local line A to determine whether the incoming end of the toll switching trunk has been connected with the proper line or to determine whether the party answering is the particular party desired. After being assured that it is either the correct number or the particular party desired, the operator instructs the local party to wait until connection is completed with the toll line. The listening key 28 may then be restored to normal position and plug 40 inserted into jack 41. Cut-oft relay 42 is thereupon operated to disconnect line relay 13 from the line. The toll operator may then actuate ringing key 44. to connect the source of ringing current 45 with line B to cause the operation of call bell 16. The ringmg key is then restored to normal and the listening key actuated in order to properly supervise the connection. In response tothe operation of call bell 4C6 the toll subscriber B removes the receiver from the switchhook and upon answering is advised by the toll operator that the local line A is connected for conversation. The operator may then restore the listening key 28 to normal position.

If the toll subscriber B wishes to attract the attention of the operator, a generator 47 located at the station on toll line B, is operated, thereby causing the operation of relay 18 bridged across the cord circuit C. The operation of relay 4L8 releases relay 25, which in releasing causes the operation of the slow operating relay 26 over a circuit from battery through the right-hand contact of relay 20, winding of relay 26 and lamp in parallel, contact of relay 25 and contact 49 of listening key 28 to ground.

Relay 26 in operating establishes a locking circuit for itself through its contact so that this relay remains operated and the lamp remains lighted after the relay 25 is again operated upon the release of the bridged relay 48. The operator upon observing the lighted condition of lamp 50 may actuate the listening key 28' to connect the operators telephone set across the cord circuit. The actuation of the listening key 28 opens contact 49, thereby releasing relay 26 and extinguishing the lamp 50. Upon learning the wishes of the toll subscriber B, the listening key may be restored to normal position.

At the conclusion of the conversation, subscriber A restores the receiver to the switchhook and subscriber B rings off by operating the generator 4L7. The restoration of the receiver to the switchhook of subscriber A releases supervisory relay 35, whereupon relay let releases, again establishing a circuit for supervisory relay 17 bridged across the cord circuit C. Relay 17 thereupon operates to light the lamp 22, which now glows continuously. The operation of the generator l7 causes the energization of slow operating relay 26, which then locks up to maintain the lamp 50 lighted. The con tinuous glowing of both of the lamps 22 and 50 serves as disconnect signals to the toll operator who may then withdraw the plugs from the jacks, restoring all apparatus of the cord circuit C to normal position. The withdrawal of the plug 5 from the jack 10, causes the release of relay 13, whereupon the lamp 11 is lighted to furnish a disconnect signal to the toll switching operator. The toll switching operator may thereupon wlthdraw the plug 6 from the jack 7, whereupon all apparatus associated with the line A- and toll switching trunk D is restored to normal position.

If after the subscriber A restores the receiver to the switchhook and before the toll operator withdrew the plug 5 from the jack 10, the local subscriber A again removes the receiver from the switchhook, the lamp 22 1s thereupon intermittently lighted to furnish a signal to the operator that subscriber A wishes to make a recall. This is accomplished in the following manner.

Upon the operation of relay 17 when subscrlber A restores the receiver to the switchhook, a short circuit is established for the right-hand winding of relay 2a, which thereupon releases its armatures. Upon the closure of the right contact of relay 24, relay 23 is operated and locked up in the manner hereinbefore described. The interrupter 29 is now connected with the lefthand open contact of relay 24: so that when relay 17 releases its armature upon the subsequent removal of the receiver from the switchhook by subscriber A, the short circuit is removed from the high resistance right-hand winding of relay 24. Relay 2% thereupon operates, connecting the interrupter 29 in circuit with its low resistance left-hand Winding and the lamp 22. The lamp is thereupon intermittently lighted. The operator upon observing the intermit tent glow of lamp 22 will actuate listening key 28 to connect the operators telephone set with the cord circuit. Upon the actuation of the key 28, contact 27 is opened, whereupon relay 23 releases to disconnect the interrupter from circuit relation with lamp 22.

The operator upon receiving instructions from subscriber A may have the desired connection completed in any desired manner.

\Vhat is claimed is:

1. A telephone exchange system comprising telephone lines, a link circuit for interconnecting the lines, a supervisory relay in the link circuit responsive to the opening and closure of a telephone line, a local relay energized over a circuit independent of the supervisory relay upon connection of the link circuit with one of the lines and deenergized upon response of the supervisory relav when the line is opened, a relay energized upon the deenergization of the local relay, a signaling device, and interrupter mechanism brought into circuit with the signaling device by the subsequent energization of the local relay upon the closure of the line.

2. A telephone exchange system comprising telephone lines, a link circuit connected with one of the lines, a supervisory relay in the link circuit responsive to the opening and closure of the connected line, a local circuit relay deenergized upon response of the supervisory relay when the connected line is opened, a third relay normally deenergized while the local relay is energized. and energized upon the deenergization thereof, a signaling device, and interrupter mechanism brought into circuit with the signaling device by the subsequent energization of the local relay when the connected line is closed.

3. A telephone exchange system comprising telephone lines, a link circuit connected with one of the lines, a supervisory relay in the link circuit responsive to the opening and closure of the connected telephone line, a local circuit relay deenergized upon response of the supervisory relay when the line is opened, a slow-to-operate relay energized upon the deenergization of the local relay, a signaling device, and interrupter mechanism brought into circuit with the signaling device by the subsequent energization of the local relay upon the closure of the line while the slow-to-operate relay is energized.

4:. A telephone exchange system comprising telephone lines, a link circuit connected with one of the lines, a supervlsory relay in the link circuit responsive to the opening and closure of the connected telephone line, a local relay deenergized upon the response of the supervisory relay when the line is opened, a slow-to-operate relay energized upon the deenergization of the local relay, a locking circuit for the slow-tooperate relay established upon the energization thereof, a signaling device, interrupter mechanism, and a circuit for the signaling device and interrupter mechanism established by the subsequent energization of a local relay and including contacts of both the slow-to-operate and the local relay.

5. A telephone exchange system comprising telephone lines, a link circuit connected with one of the lines, a supervisory relay in the link circuit responsive to the opening and closure of the connected telephone line, a local relay, deenergized upon the response of the supervisory relay when the line is opened, a slow-to-operate relay energized upon the de'e'nergization of the local relay, a locking circuit for the slow-to-operate relay established upon the energization thereof, a signaling device, interrupter mechanism, and a circuit for the signaling device and interrupter mechanism completed by the subsequent energization of the local relay upon the closure of the connected telephone line and including engaged contacts of the slowto-operate and local relays and a winding of the local relay.

6. A telephone exchange system comprising a telephone line, a link circuit for c0nnecting with the telephone line, a supervisory relay in the link circuit responsive to the opening and closure of the telephone line, a local circuit relay energized upon the connection of the link circuit with the telephone line, a short circuit for the local relay completed by the energization of the supervisory relay upon the opening of the line thereby deenergizing the local relay, a slowto-operate relay energized upon the deonergization of the local relay, a signaling device, and interrupter mechanism brought into circuitwith the signaling device by the subsequent energization of the local relay upon the deenergization of the supervisory relay when the line is closed.

7. A telephone exchange system comprising a telephone line, a link circuit for connecting with the telephone line, a supervisory relay in the link circuit responsive to the opening and closure of the telephone line, a local circuit relay energized upon the connection of the link circuit with the telephone line, a short circuit for the local-relay completed by the energization of the supervisory relay upon the opening of the line thereby denergizing the local relay, a slowto-operate relay energized upon the deenergization of the local relay, a signaling de vice, interrupter mechanism, and a circuit for the signaling device and interrupter mechanism completed by the subsequent en ergization of the local relay when the line is closed and including contacts of both the slow-to-operate and local relays.

8. A telephone exchange system comprising a telephone line, a link circuit for connecting with the telephone line, a supervisory relay in the link circuit adapted to be controlled over the telephone line when connected With the link circuit, a local circuit relay energized upon the connection of the link circuit with the telephone line and deenergized upon the energization of the supervisory relay when the line is opened, an operators telephone set, a listening switch for connecting the operators telephone set with the link circuit, a slow-to-operate relay energized upon the deenergization of the local relay, a locking circuit for the slow-tooperate relay completed upon the energization thereof and including a contact of the listening switch, a signaling device, and interrupter mechanism brought into circuit with the signaling device by the subsequent energization of the local circuit relay when the telephone line is closed.

In witness whereof I hereunto subscribe n1y7na1ne this 21st day of September, A. D. 191

RAY S. WILBUR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.